Plate IX.
Fig.
1. Fenestella fossula Lonsdale, p. 89. 269., nat. size.
la. Magnified representation of a portion of a cast of the cellular
surface, figured from a specimen in the collection of Mr.
Darwin.
2. Fenestella internata Lonsdale, p. 87. 89. 94, 95. 269., nat.
size.
2a. Cellular surface magnified.
2b. Magnified representation of the granular outer layer, and
sharply fibrous or minutely tubular inner layer of the non-
cellular surface.
3. Fenestella ampla Lonsdale, p. 87. 94, 95. 268. Cast of
cellular surface, nat. size, from a specimen belonging to Mr.
Darwin.
3a. Non-cellular surface, nat. size.
3b. Magnified representation of the fibrous or minutely tubular
structure of the inner layer of an old portion of the coral, and
of the dorsal terminations of the cells.
3c. Magnified representation of a cast of the cellular surface.
3d. Magnified side-view, showing the range of the cells, and the
minutely tubular structure of the non-cellular portion.
4. Hemitrypa sexangula Lonsdale, p. 269., nat. size.
4a. Magnified view of a portion of the same, figured from a speci-
men belonging to Mr. Darwin.
Plate X.
1. Allorisma curvatum Morris, p. 91. 270.
2. Pachydomus globosus Morris, p. 91. 272.
3. A young individual of the same.
4. This figure illustrates a small specimen supposed to belong to
the same species, and exhibits the peculiar characters of the
muscular impressions : it may, however, be only a young state
of Pachydomus laevis.
Plate XI.
1. Orthonota? costata Morris, p. 91. 273.
2. A cast of the same species, showing the impressions of the
mantle and adductor muscles.
3. Pachydomus carinatus Morris, p. 91. 273.
4. A cast of the same, showing the muscular impressions.
Plate XII.
Eurydesma cordata , p. 91. 276. The upper figure exhibits the small muscular impressions pro- ceeding, from under the cardinal area, towards the adductor muscle. The two lower figures are the right and left valves of the same species, showing the dental characters, and the broad striated ligamental area.
